Process for refining turpentine



Jan. 19, 1943. J. o. REED 2,308,715

PROCESS FOR REFINNG vTURPENTNIE Filed May 2, 1940 INVENTOR Jesg O. Reed Patented Jan. 19, 1943 Zaans PROCESS FOR REFINING TURPENTrNE J esse` O. Reed, Washington, D.- C.; dedicated to the free use of the People in the territory of the l Y United States Application May l2,'1940,saranno.332,919 v j iciaim. (cieco-666) Y `Grante1taethe act of March' a, 1ste, as f amended sparso., 192s; 37o o. vc.. '157) vThis application is made under the act of March 3,1883, as amended by the -act of 'April 30, 1928, and the invention-herein* described and claimed, if patented, may be manufactured and used by orfor the Goverment of the United States of America for governmental purposes Without the payment to me of' any royalty thereon. v I hereby dedicate the invention herein de'- scribed to the free' use of the people in the 'territory of the United States to take eiect on the granting of a patent tome.

Gum spirits of turpentine as it comes from the condenser of aturpentine still is mixed with a Water condensate calledI low wines containe ing Water-soluble acids. Due tothe difference in the gravities ofthe acid-containing water and turpentine an immediate separation takes place in the barrel or separator used to receive the discharge from the said condenser. The turpentine which comes to the top of the separator barrel is drained off and the waterjis automatically discharged from the bottom. This separation is vnot complete, however, since some offthe 'acidic Water remains, not only entrained in 'the' turpentine, but dissolved lby the turpentine. The

'solubility of'vvater inturpentine increases with an increase inA temperature, so that the ,Warmer the turpentine, vvhen'itis discharged from the condenser, the morewater iscarried insolution by theturpentine. .'.The presnceijoi both .ther entrained and the dissolved' water in the turpentine hasbeen shown by "experiments to b e one of the principal-:causesvof turpentine' d eterioration and discoloration vv'vhen placed in metal 'containers Furthermore, 'when' the'tur'- pentine' is Storedin glue lined wooden barrels, leakage often occurs because the water acts to soften the glue. In metal drums the acid-containing water attacks the metal or coating of the container causing contamination and discoloration of the turpentine with a corresponding loss of market value.

The general object of my invention is to provide a process and apparatus for conditioning turpentine so that deterioration of turpentine during storage will be reduced to a minimum.

VAnother object of my invention is to rene and purify turpentine so that it can be stored in cheap uncoated metal containers without discoloration. 4

A further object of my invention is to provide simple equipment for conditioning turpentine at the turpentine still which can be readily fabri- `cated at small cost, and which issimple, automatic, and inexpensive in operation.

The accompanying drawing illustrates, diagrammatically, a convenient arrangement -of an `apparatus for carrying out my invention'.4 The apparatus comprises a chamber I, which receives the turpentine and loW` Wines`from the condenser outlet 2 of the turpentine still.'v The vturpentine separates from the flow wine inchamber I and comes to thetop.' vThe loW wine or acid-containing Water settles vto the bottom and Vis discharged 'as waste through a pipe 3,con-

nected at the bottom of chamber I, while vthe `turpentine discharges--througha pipe 4, connected at the top. By correctly adjusting the height, o1' pipe 3, a continuous separation 'and 'discharge of turpentine and V10W wines entering chamber I can be accomplished. vThe separated turpentine containing entrained 'and dissolved acidic Water discharges into chamber 5 at a point near the bottom.

Chamber 5 is filled With salt 6 in coarse granular form over several inches of gravel 'lL Turpentine enters the chamber 5 just above the-top layer of the gravel "I, and is discharged through the pipe 9, tapped in at the top of the chamber..

the acidic Water-contaminated turpentinel from chamber I passes through the vsalt 6' in chamber 5, the entrained Waterand some of the dissolved waterl in the turpentine dissolves the salt and forms a brine which is considerably be withdrawn from chamber 5 through a'spigot 8. Turpentine from chamber'v 5 flows through the lpipe 9 into another chamber l0 and is introl ducedinto chamber I0 in-small streams-through a perforated pipe II disposed near the bottom of the chamber, or by any other suitable means. Chamber I0 is lled with packing I2, such as iine washed gravel I2, to a level several inches below a discharge pipe I3. At the top level of packing l2, cool water is continuously introduced into the chamber I0 through pipe I4, and discharged as Waste through pipe I5, which is elevated similarly to the pipe 3 of chamber I to provide a continuous discharge of turpentine and water from chamber I0. As the turpentine from chamber 5 is introduced into chamber I0 in thin streams, it is brought into intimate contact with the water by means of the packing I2. Having a low specific gravity, the turpentine comes to the top of the water and in doing so becomes thoroughly washed and cooled to approximately the temperature of the water owing continuously into chamber I 0 through pipe I4. In this washing operation the water-soluble acids are removed from the entrained water-free turpentine from chamber 5. due to the fact that the wash water dlutes the acid-'solution and reduces the solubility of the acid thereof, and are carried away in the discharge water through pipe I5. In addition, the turpentine is cooled so that much of the acidic water dissolved by the turpentine is either carried away by the wash water through said pipe I5 or made ready for removal in alater stage of the process. Althoughvthe turpentine entering chamber I0 is perfectly clear and apparently free of impurities, I have discovered that it contains a gum-like material which is removed from the turpentine by the Washing operation and settles between the turpentine and water layer in chamber I0. The composition of this gum-like material is not known, but its removal from the turpentine appears to be a factor contributing to the result that the turpentine can` be stored for a long period without discoloration in uncoated metal containers.

The turpentine discharged from chamber il) through pipe I3 contains some entrained and dissolved water which'is removed from the said turpentine in chamber I6 with an apparatus similar to that of chamber 5. The washed turpentine enters chamber I5 near the bottom. Chamber I6 is lled with salt I'I in coarse Vgranular form `over gravel I8 several inches in height. Turpentine enters said chamber I6 just above the top layer of gravel I8 and discharges through pipe I9. As the turpentine, containing water from chamber ID, passes through said salt I'I in chamber I6, the water in said turpentine dissolves salt I'I and forms a brine which, having a higher specific gravity than turpentine, settles to the bottom of chamber I6 in gravel I3. When desired, the brine accumulated in gravel I8 can be Withdrawn from chamber I6 through spigot 2D. The conditioned turpentine, comprising the nished product of my invention, is discharged through pipe I9 into suitable containers forV a fairly constant temperature of the turpentine at the discharge of the apparatus. More efficient results are obtained in the drying of the cooled turpentine in chamber I6, because of the decreased amount of water held in solution in the turpentine as compared tothe turpentine handled in chamber 5. Turperitine discharged from the apparatus at a fairly uniform and constant temperature is of considerable value in packaging because more uniform volumes and Weights are madepossible than with turpentine of varying temperatures due to the fairly large coefficient of expansion which turpentine possesses.

In operation 4the ow of turpentine through the apparatus is continuous and it is effected by gravity, the rate of flow depending upon the rate of discharge from condenser outlet 2. The amount of washing water used is adjusted so that theturpentine is cooled to a temperature within several degrees of the temperature of the wash water entering chamber 5. The acidity of the wash water being discharged can also be used in determining `the desired rate of iiow of the wash water.

It is obvious that various modications of the aboveAV apparatus and method may be resorted to lwithout departing from thespirit and scope of my invention, For example, chamber 5 may be eliminated and the turpentine run directly from chamber i to chamber -IIJ by the expedient of introducing suicient wash water into chamber I0 to compensate for results which would have been obtained by the use of chamber 5. The use of chamber 5, however, results ,in` a more efficient operation and a more economical use of wash water. Also, if the wash water in chamber I0 is cool enough, the turpentine vwithdrawn therefrom is in a high state oi refinement, and for many purposes the chamber I6 may be omitted. However, this does not preclude the use of salt chambers, in addition to the two illustrated, at

any point inthe process, or additional washing chambers.

Having thusdescribed my invention, I cla-im:

The method of rening turpentine condensate comprising separating out by gravity entrained low Wines, recovering the remainder of the product containing turpentine and dissolved and entrained acidic water, introducing the recovered product at the bottom of a column of salt, whereby the acidic water dissolves the salt of said co1- umn formingV a brine, permitting said brine to separate by gravity, washing andv cooling the remaining product by spraying it in a stream of cool water, collecting the supernatant liquid and introducing it at the bottom of another column of salt whereby' the water dissolves the salt of said column to form a brine, permitting said brine to separate by gravity, and recovering the supernatant liquid as the refined product.

JESSE O. REED. 

